1. Field of the Invention
The present invention relates to a laser chemical vapor deposition (CVD) device and a laser CVD method, which are applied for correcting deficiencies (defects) in photomask patterns and for correcting deficiencies in wiring or insulating patterns formed over the substrate of a liquid crystal display device.
2. Description of the Related Art
Conventionally, laser CVD devices and laser CVD methods are used for permitting selective film formation in infinitesimal areas and, more particularly, are well known to be applied for correcting deficiencies in photomask patterns and deficiencies in wiring or insulating films formed over the substrate of a liquid crystal display device.
Such laser CVD devices and methods are described in the Japanese Patent Application Laid-open No.63-164240, the Japanese Patent Application Laid-open No.63-65077, the Japanese Patent Application Laid-open No.64-47032, the Japanese Patent Application Laid-open No.3-166376 and the U.S. Pat. No. 4,801,352.
Of these, all of the laser CVD methods described in the Japanese Patent Application Laid-open No.63-164240, the Japanese Patent Application Laid-open No. 63-65077, the Japanese Patent Application Laid-open No. 64-47032 laser CVD method and the Japanese Patent Application Laid-open No. 3-166376 are carried out in a reduced-pressure chamber. By contrast, the laser CVD method disclosed in the U.S. Pat. No. 4,801,352 is performed in the atmosphere.
Today, when substrates over which films are to be formed have significantly increased in size, the laser CVD device and method described in the U.S. Pat. No. 4,801,352 can be considered useful because, unlike other known devices, it requires no chamber in which the substrate over which a film is to be formed is accommodated and the pressure is reduced. Therefore the laser CVD device of the U.S. Patent needs no large size equipment, and moreover can increase the throughput. However, when the laser CVD device described in the U.S. Patent is used, as the film formation face of the substrate is exposed to the atmosphere before a film is formed thereon, there is a fear that the film formed may come off the substrate face. Particularly, when the device is applied for correcting deficiencies in photomask patterns and deficiencies in wiring or insulating films formed over the substrate of a liquid crystal display device, a film formed at a defect portion is in contact with the substrate face in a limited area or a small area, thereby being susceptible to this problem. Further, the film itself often becomes cracked.